I've been working on implementing Leisa Reichelt's design for the new node add/edit form. Gábor Hojtsy started the process off by creating a patch to move the submit buttons up to the right, and separate the node form into a "Content" and a "Meta" tab. I refined his patch to make the horizontal tabs a reusable form element, and in the current state of the patch, the node form looks as pictured:
The next step in implementing the design was the pseudo-collapsible fieldsets on the "Meta information" page. The basic concept was to leave information available in a readable state, yet not take up so much room so as to block other information from the screen. While the layout I created isn't exactly like the design, I believe it cleanly captures the essence of the idea without requiring too many changes to the underlying code. With my current patch, the "Meta information" tab appears as pictured:
I like what I've done a lot, but what is usable for one person might be completely unusable for everyone else. I'm sure there's room for improvement, so please feel free to comment on either of the issues (horizontal tabs) (modified fieldsets) or add a comment to this post to voice your thoughts or concerns. There are many opinions on what makes for good usability, and the more opinions we get, the more accurate a picture we can make of what is most usable overall. Thank you!